In many applications, it is a problem to make a secure and dependable electrical connection through a rotating shaft for components of an electrical apparatus. This is particularly true in electrical apparatus such as generators and the like where the rotating shaft may operate at variable speeds up to 30,000 R.P.M. or more and at temperatures on the order of 300.degree. to 350.degree. F. Under such conditions, electrical connections must be capable of withstanding high centrifugal forces and other severe environmental conditions.
In both commercial and military fields, it is also highly desirable for electrical connections to accommodate assembly and disassembly without damage to component parts. For instance, in high frequency generators for aircraft such electrical connections are needed to interconnect the exciter to the rectifier and/or the rectifier to the main field of the generator where the various component parts rotate with the shaft. In the past, lead wires were either fed directly through the shaft or joined in a brazed joint outside the shaft.
In either case, the resulting assembly was less than completely satisfactory. Where the lead wires were fed directly through the rotating shaft, the high centrifugal forces coupled with high temperature would eventually cause the shaft to cut through the insulation of the lead wires to thereby create a short circuit and/or damage to components connected thereby, and where the lead wires were joined in a brazed joint outside the shaft, it has proven to be difficult, if not impossible, to disassemble the generator in an efficient and effective manner to replace damaged component parts. Moreover, it has generally been thought that connectors such as screws were undesirable for a number of reasons.
Among the reasons for avoiding screws is their tendency to loosen when subjected to vibration and centrifugal forces. This has generally been thought to be relatively critical in view of the fact that the screws and screw threads have usually been required to carry electrical current. As a result, fasteners such as screws that may loosen and/or insulation material that may shrink are avoided in electrical connections.
While overcoming problems of this type, it is desirable to provide a secure electrical connection between component parts on a rotating shaft assembly of an apparatus such as a high frequency generator. It is also desirable to eliminate the difficulty or impossibility of replacing component parts by facilitating assembly and disassembly in the electrical connection. Further, it is desirable to provide a component part rotating shaft electrical connection that is inexpensive to manufacture and maintain.
The present invention is directed to overcoming the above stated problems and accomplishing the stated objects.